Each year, the Portland City Council designates trees for Heritage Tree status, based on their age, size, type, historical association and/or horticultural value. There are currently 281 such trees, spread throughout the city: from Forest Park in the West Hills, to the Lan Su Chinese Garden in Old Town/Chinatown, out to Happy Valley and Powell Butte Nature Park in the east; from St. Johns and North Portland, to Sellwood and Reed College in the south. That's a lot of territory to cover.

PDX Trees makes it easy to find and and enjoy them. With this app, you can:

Search for nearby trees and see them on a map.

Tap a pin to see the name and view details for that particular tree.

Take and upload a photo of a Heritage Tree you're visiting.

View photos of the tree taken by other tree enthusiasts.

Email a friend about the tree.

Read more about a type of tree from Wikipedia, without leaving the app.

I've had working prototypes of this app on my phone since late August. As I wandered around locating these trees, I realized I didn't want to build a simple reference app. Somehow, that didn't seem enough. I wanted this project to be more involved and engaging, to find ways for tree fans to participate and have a reason to visit these trees again and again.

Standing under a Japanese maple on a hot August day, I wondered what it looked like in October, or January. And that's when it hit me: Let's build a collection of images of Portland's Heritage Trees together!

With the first release of the PDX Trees iPhone app, I have two primary goals:

To make it easier for citizens and visitors alike to find and enjoy these trees.

To build a set of images as a community that shows how Portland’s Heritage Trees change over the seasons and over the years, and to see these trees through each others’ eyes — and cameras.

I'll release a version that will run on the iPad after the release of iOS 4.2, and have plans for a full-screen iPad edition next year.

I realize that not everyone has access to an iPhone, so it’s important to me to bring the tree locations and photos to other platforms. I'll be working on web and mobile web versions so more people can view and contribute to the project. In the meantime, here's a video of the app in action: